An infinite-dimensional linking theorem without upper semi-continuous assumption and its applications

On an estimate of the eigenvalues for an

On an estimate of the eigenvalues for an infinite-dimensional matrix and its application to the problem of the completeness of an eigenvector system of a completely continuous operator

✍ V.A. Strauss 📂 Article 📅 1998 🏛 Elsevier Science 🌐 English ⚖ 837 KB

We consider spectral properties of several infinite-dimensional matrices and show that matrices of this type can be used as a representative model for the Gram operator of a sesquilinear form. The representation is applied to the study of the completeness problem of an eigenvector system for a G-sel